Ignition chamber for explosive motors



May 22, 1934. H. F. MOKNIGHT IGNITION CHAMBER FOR EXPLOSIVE MOTORS Filed July 30, 1932 Patented May 22, 1934 assen IGNITION CHAMBER FOR EXPLOSIVE MOTORS Harry F. McKnight, Elmhurst, Ill.

Application July 30, 1932, Serial No. 626,598

'7 Claims.

This invention relates to internal combustion engines, and its object is to improve the economy of such engines in the use of fuel, and to secure a more uniform working pressure by distributing the force of the explosion or burning of the gases over a longer period than is possible with standard constructions. Another object is to provide facilities for igniting a small portion of the charge partially segregated from the main charge and then permitting the flame to travel from this ignited portion to the remainder of the charge. Another object is to provide a construction which may be applied to existing engines for securing the results already mentioned. The invention 5 consists in certain features and elements of construction in combination as herein shown and described, and as indicated by the claims.

In the drawing: Figure 1 is a partial conventional view showing an internal combustion engine in the side elevation with devices embodying this invention applied thereto.

Figure 2 is a vertical axial section taken through a portion of an engine cylinder, with an auxiliary combustion chamber embodying this invention mounted thereon.

Figure 3 is an elevation of the device'shown in Figure 2, taken partly in section.

Figure 4 is a horizontal detail section taken as indicated at line 4--4 on Figure 3.

40 themselves are shown at 2 inserted in suitable threaded openings in the devices, 10, respectively. The wiring diagram for the ignition is partially indicated in broken lineswith the distributor cut lined at 3.

In Figure 2 there is shown the upper portion of one engine cylinder, 1, in which a clearance space is provided at 4 above the upper limit of movement of the piston, 5. An inlet port, 6, and an exhaust port, 7, communicate with this space, and in the head of the cylinder is shown at opening, 8, threaded to receive the usual spark plug for igniting the charge in the space, 4. My invention contemplates more or less segregating a small portion of the charge and applying the electrical ignition to this portion While permitting the small ignited charge to initiate combustion of the remainder. Figure 2 shows an auxiliary combustion chamber, 10, having a reduced threaded portion at 10 which is screwed into the threaded opening, 8, thus placing the chamber, 10, in communication with the interior of the cylinder, 1. The device, 10, includes an upper chamber, 11, and a lower chamber, 12, with a vertically movable valve member, 13, positioned to control communication between these chambers. The upper chamber 11, is shown with a laterally opening port threaded to receive the spark plug which is partially shown in dotted outline at 2, and whose ignition points are indicated also in dotted outline at 9 and 9*, within the chamber, 11; Between the spaces, 11 and 12, the interior wall of the device is formed with a valve seat, 14, upon which the valve, 13, fits when it stands at its upper limit of movement. Normally, however, said valve is carried by gravity to its lower limit, thereby affording communication between the chamber, 11, and thespace, 12, by way of an annular passage, 15, and ports, 16, leading to them from the space adjacent the seat, 14.

The valve, 13 itself is formed with an upwardly tapering bore, 1'7, which extends entirely through the valve member and affords limited communication between the throat-way, 18, in the threaded stem of the device, 10, and the upper chamber, 11. When the piston, 5, rises toward the head of the cylinder, thus compressing a charge of fresh gas therein, a portion of this gas is forced upwardly through the throat, 18, and bore, 17, into the chamber, 11, and the pressure and velocity of this gas acting against the tapering wmls of the port, 17, tend to hold the valve against the seat, 14, up to the instant when the spark occurs between the points, 9 and 9 and ignites the small charge of gas thus pocketed in the chamber, 11. The force of the explosion thus produced tends to drive the valve, 13, downwardly, unseating it at 14 and permitting the ignited gas or flame to travel through the ports, 16, and annular passage, 15, into the lower space, 12. The expansive force of the burning gases is suflicient, however, to drive them past the lower beveled surface, 19, of the valve, 13, into the passage, 18, and thence into the interior of the cylinder, 1. At the same time a portion of the burning gases may be driven directly through the bore, 1'7, of the valve, 13. Thus following the ignition of the small quantity of gas in the chamber, 11, the flame is communicated through the throatway, 18, to the main charge, which, of course, fills the space, 18, as well as the upper portion, 4, of the cylinder, 1.

I have found that apparently this method of igniting the main charge produces a more perfect combustion of the gas than is secured when the spark plug extends into the cylinder head itself. This is probably due to the fact that an explosion occurring in the engine cylinder tends by its explosive forces to drive a considerable portion of the fresh gas away from the point of ignition, so that some of this gas may be pocketed in the inlet or exhaust ports, and other portions of it remain too remote from the spark plug points to become ignited during the limited period permitted by the engine cycle. With my arrangement the gas which is directly subjected to the electric spark is a comparatively small quantity, and it is so confined that the entire quantity is ignited promptly and before the explosion begins to take effect upon it. Then the flame produced by this small quantity of burning gas and forced into the main charge becomes a center of ignition which is much greater in area than the spark produced by the ordinary spark plug. This flame thus ignites the remainder of the gas much more efiiciently than an electric spark could, but even ignoring the effect of the explosion above discussed. Whatever may be the true explanation, I find upon experiment that the gas burns both in the cylinder and in my auxiliary device, 10, without leaving any sooty deposit whatever; also that the power of the engine is increased markedly, and that its operation is noticeably simpler than with the standard arrangement of spark plugs in the cylinder heads.

To dissipate the heat produced by the explosions in the chamber, 11, I have shown the device provided with cooling fins, 20. It will be understood that the form of my explosion chamber shown herein is chosen mainly for purposes of illustration, and that if desired an auxiliary chamber for this purpose may be incorporated in the initial construction of the engine instead of being made as an appliance to be added afterward. The form shown, however, may be manufactured and marketed as an accessory device for improving the performance of existing engines.

Therefore, while there is shown and described herein certain specific structure embodying the invention, it will be manifest to those skilled in the art that various modifications and re-arrangements of the parts may be made without departing from the spirit and the scope of the invention, and that the same is not limited to the particular form herein shown and described, except in so far as indicated by the appended claims.

I claim:

1. In combination with an internal combustion engine, an auxiliary chamber associated therewith, means affording communication between said chamber and the engine cylinder during compression, whereby a portion of the main fuel charge passes into said chamber from the engine cylinders, separately timed ignition means in the chamber for firing such partial charge, and movable means for obstructively permitting the ignited gas to expand into contact with the compressed fuel in the cylinder to ignite it.

2. In combination with an internal combustion engine, an auxiliary chamber associated therewith, means affording communication between said chamber and the engine cylinder during compression, whereby a portion of the fuel charge passes into said chamber, separately timed ignition means in the chamber for firing such partial charge, and a valve member partially obstructing communication between said chamber and the cylinder adapted to be seated by the compression and to be forced off its seat by the expansive force of the ignited partial charge in the chamber.

3. In combination with an internal combustion engine, an auxiliary chamber associated therewith, means afiording communication between said chamber and the engine cylinder during compression, whereby a portion of the fuel charge passes into said chamber, separately timed ignition means in the chamber for firing such partial charge, and a valve member seating normally toward saidchamber under the force of compression in the cylinder, said valve having a passage extending through it, for admitting the partial fuel charge from the cylinder to the chamber, and said valve controlling an additional passage affording communication between the chamber and cylinder when the valve is unseated.

4. In combination with an internal combustion engine, an auxiliary chamber associated therewith, means affording communication between said chamber and the engine cylinder during compression, whereby a portion of the fuel charge passes into said chamber, separately timed ignition means in the chamber for firing such partial charge, and a valve member partially obstructing communication between the chamber and the cylinder, said valve being adapted to seat toward the chamber, and being formed with a passage tapering toward the chamber, whereby the force of the compression tends to seat the valve while said passage admits a partial fuel charge to the chamber, said valve being forced in the opposite direction when said charge is ignited in the chamber.

5. In combination with an internal combustion engine, an auxiliary chamber associated with the engine cylinder, with a passage affording comed to be seated by the compression in the cylinder, the wall of the passage including a shoulder which stops the valve at the opposite limit of its travel, and said valve being beveled adjacent said shoulder, ignition means in the chamber for firing a partial charge of fuel therein, the expansion of such ignited charge serving to unseat the valve, and the beveled surface of the valve permitting escape of the ignited gas between the valve and the shoulder for contact with the main body of gas in the cylinder.

6. In combination with an internal combustion engine provided with a threaded opening leading into its cylinder for the reception of a spark plug, an auxiliary chamber formed with a threaded stem to fit in said opening, said chamber having a threaded opening to receive the spark plug, said stem having a throat-way affording communication between the chamber and the interior of the cylinder, a valve interposed between said throat-way and the chamber seating toward the chamber and adapted to be seated by the force of the compression in the cylinder, said valve having a passage to admit compressed gas from the cylinder to the chamber for ignition therein, whereupon the force of expansion of the ignited gas serves to unseat the valve and permit said gas to commingle with the remainder of the fuel charge in the engine cylinder.

7. In combination with an internal combustion engine, an auxiliary chamber associated therewith, a passage affording communication between said chamber and the engine cylinder, a valve guided to vibrate in said passage between stops, said valve having a restricted passage to admit 

